Encoded data recording apparatus and mobile terminal

ABSTRACT

In a mobile terminal provided with an encoded data recording function, there is assumed a condition in which a picture frame transmitted from the terminal of a communication partner is reproduced by means of decoding processing and is displayed on a LCD ( 34 ) during wireless TV phone communication. In this condition, when a user carries out a picture recording start operation, display picture data reproduced by means of decoding processing in the multimedia processing section ( 24 ) to be displayed on the LCD ( 34 ) are recorded in a main recording section ( 26 ).

TECHNICAL FIELD

[0001] The present invention relates to an encoded data recordingapparatus and a mobile terminal used for example in a system handlingencoded data.

BACKGROUND ART

[0002] In recent years, various information transmission systems such asa broadcasting system, a cable communication system and a mobilecommunication system have been put to practical use or planed, and as aresult thereof, various terminals have been developed.

[0003] For example, in a mobile communication system, mobile terminalssuch as mobile phones and PDAs (Personal Digital Assistants) are used.In this kind of terminals, not only voice communication service, butalso various transmission services such as SMS (Short Message Service),electronic mail service and information distribution service usingwireless internet are available. When data including a large amount ofinformation such as motion picture data (or video data) are tried totransmit in the mobile communication system, they cannot be transmittedas they are because the transmission path band causes a bottleneck.

[0004] So, a compression/extension processing of video data is requiredin transmitting motion picture data wirelessly, and as one means ofrealizing the processing, the employment of a compression/extensionscheme called MPEG-4 (Moving Picture Experts Group-4) is beingdiscussed.

[0005] MPEG-4 represents data having correlations on the time axis suchas video data with an initial frame and a difference frame. The initialframe is called I-Frame (Intra-coded Frame) and contains whole pictureinformation elements (absolute value information) of one pictureobtained by being compressed as a still picture. That is, the I-Framecomposes a picture frame having an independent meaning alone. Incontrast thereto, the difference frame is called P-Frame(Predictive-coded Frame) and mainly contains difference informationbetween the picture of the current frame and the picture of thepreceding frame. And, in the first timing after the start oftransmission an I-Frame is transmitted, and in the subsequent frametimings P-Frames are transmitted sequentially. By using MPEG-4, motionpicture data having an amount of information equivalent to several Mbpscan be transmitted with being compressed to several ten Kbps.

[0006] However, in a system employing such a compression/extensionscheme, if the video recording button of the apparatus is pushed inreceiving data, only difference frames can be recorded, and as a resultthereof, it becomes difficult to reproduce pictures effectively from therecorded video data.

[0007] So, in MPEG-4, an idea that the picture of each P-Frame isdivided into a large number of blocks and that absolute valueinformation is transmitted in a part of blocks selected optionally fromeach P-Frame is employed. The blocks in which the absolute valueinformation is transmitted are called a macro-block respectively. Byreceiving a plurality of P-Frames and synthesizing the macro-blocksthereof, the apparatus can reproduce one picture data equivalent topicture data of the I-Frame.

[0008] Therefore, even if the picture recording button of the apparatusis pushed in receiving picture data, one picture data comprisingabsolute value information can be reproduced by receiving the samenumber of P-Frames as the macro-blocks constituting one picture.

[0009] However, in a period from the start of video recording to the endof receiving the same number of P-Frames as the macro-blocksconstituting one picture, one picture data comprising absolute valueinformation cannot be reproduced. The above-described period lasts, forexample, about 10 seconds. As a result thereof, users may fail to recordvideo data of desired scenes.

DISCLOSURE OF INVENTION

[0010] The present invention has an object of providing an encoded datarecording apparatus and a mobile terminal adapted to be able to recordhigh-quality data immediately after inputting a recording instructioneven if the recording is begun during data input or data reception.

[0011] In order to attain the above-described object, the encoded datarecording apparatus according to the present invention is an apparatusrecording encoded data composed of first data generated in the initialframe timing and a plurality of second data generated respectively inthe subsequent frame timings and comprises an encoded data input meansfor inputting the encoded data, a data reproduction processing means forreproducing the original data based on the first data and the seconddata of the encoded data inputted by the data input means, a recordingperiod specifying means for specifying the recording period of theencoded data from a user of the apparatus, and a recording controlmeans. And, when the recording period is specified by the recordingperiod specifying means in inputting the encoded data, the original datareproduced by the data reproduction processing means in the recordingperiod concerned is recorded in a recording medium by the recordingcontrol means.

[0012] Therefore, according to the present invention, when a recordinginstruction is inputted in receiving data, the original data reproducedby the data reproduction processing means will be recorded in therecording medium from this time on. Accordingly, high-quality originaldata equivalent to the first data can be recorded immediately after therecording instruction was inputted. Therefore, recorded data arereproduced, high-quality data can be reproduced from the time of havinginputted the recording instruction.

[0013] Moreover, the present invention is characterized in that therecording control means records original data reproduced by the datareproduction processing means in the recording medium in the first frametiming of the recording period and in that it records second datainputted by the encoded data input means in the recording medium in theframe timings following the first frame timing respectively.

[0014] Further, the present invention is characterized in that therecording control means re-encodes original data into first data and aplurality of second data when it records reproduced original data in therecording medium. And, the present invention is also characterized inthat the first data and the plurality of second data obtained by there-encoding are recorded in the recording medium.

[0015] Due to such a composition, original data equivalent to first dataare recorded only at the starting time of recording, and in thesubsequent recording period inputted first data is recorded as it is.Accordingly, the amount of data recorded in the recording medium can bereduced substantially through the recording period in comparison tostoring reproduced original data. Therefore, the storage capacity of arecording medium can be used more effectively, and it becomes possibleto prolong the recording time of data.

[0016] Further, in the present invention, the recording control meanstemporarily holds original data reproduced by the data reproductionprocessing means in the recording period till the input period of theencoded data ends. And, the present invention is also characterized inthat after the end of the input period of the encoded data thetemporarily held original data are re-encoded in first data and aplurality of second data and are recorded in the recording medium.

[0017] Due to such a composition, the amount of data recorded in therecording medium can be reduced substantially to prolong the datarecording time. Moreover, it becomes possible to carry out theprocessing of re-encoding reproduced original data into first data andsecond data except in the receiving period and the recording period ofencoded data. As a result thereof, no concentrated processing load canbe realized in receiving and recording encoded data, thereby reducingthe processing burden of a CPU or a DSP.

BRIEF DESCRIPTION OF DRAWINGS

[0018]FIG. 1 is a view showing the schematic organization of a mobilecommunication system that is a first embodiment of a data transmissionsystem in which an encoded data recording apparatus according to thepresent invention is used;

[0019]FIG. 2 is a view showing the layer structure of a multimediatransmission system according to MPEG-4;

[0020]FIG. 3A and FIG. 3B are views showing the appearance of a mobileterminal that is a first embodiment of the encoded data recordingapparatus according to the present invention respectively;

[0021]FIG. 4 is a block diagram showing the functional composition ofthe mobile terminal shown in FIG. 3A and FIG. 3B;

[0022]FIG. 5 is a view for illustrating the operation of a video datacompression scheme using MPEG-4;

[0023]FIG. 6 is a view showing a first example of the recordingoperations of video data carried out by means of the mobile terminalshown in FIG. 4;

[0024]FIG. 7 is a view showing a second example of the recordingoperations of video data carried out by means of the mobile terminalshown in FIG. 4;

[0025]FIG. 8 is a block diagram showing the functional organization of amobile terminal that is a second embodiment of the encoded datarecording apparatus according to the present invention;

[0026]FIG. 9 is a view showing the recording operations of picture datacarried out by means of the mobile terminal shown in FIG. 8;

[0027]FIG. 10 is a block diagram showing the functional organization ofa mobile terminal that is a third embodiment of the encoded datarecording apparatus according to the present invention; and

[0028]FIG. 11 is a view showing the recording operations of video datacarried out by means of the mobile terminal shown in FIG. 10.

BEST MODE FOR CARRYING OUT OF THE INVENTION

[0029] Now, several embodiments of the encoded data recording apparatusaccording to the present invention will be described with reference tothe drawings.

(First Embodiment)

[0030] In a first embodiment of the present invention, the presentinvention is applied to a mobile terminal having an encoded datarecording function. It is assumed that a picture frame transmitted fromthe terminal of a communication partner side is decoded and displayed ona display section during communication by means of wireless TV phonesusing MPEG-4. When a user carries out a recording start operation inthis condition, decoded video data generated to be displayed on thedisplay section are recorded sequentially in a main recording sectiontill a video recording end operation is carried out.

[0031]FIG. 1 is a schematic organization view of a mobile communicationsystem according to this first embodiment. In the same figure, aplurality of base stations BS1, BS2, . . . are distributed in a servicearea covered by the system. These base stations BS1, BS2, . . . areconnected respectively to a network NW. Mobile terminals MS1, MS2, . . .are connected respectively to the nearest base stations BS1, BS2, . . .over radio channels and are further connected from these base stationsBS1, BS2, . . . to the network NW. In the network NW, corresponding tothe calling requests of the mobile terminals MS1, MS2, . . . , aprocessing for connecting between the mobile terminals MS1 and MS2 bymeans of switching is carried out. And, once a communication link hasbeen established between the mobile terminals MS1 and MS2 by means ofthe switching connection processing, TV phone communication issubsequently permitted between these mobile terminals MS1 and MS2.

[0032] Moreover, as the above-described wireless access scheme, a W-CDMA(Wideband-Code Division Multiple Access) scheme is, for example, used.As other wireless access schemes, a cdma 2000 scheme, a FDMA (FrequencyDivision Multiple Access) scheme, a TDMA (Time Division Multiple Access)scheme, or a Narrowband CDMA scheme may be also employed.

[0033]FIG. 2 is a view showing the scheme of wireless TV phonecommunication in the mobile communication system by means ofmultiplexing transmission of motion picture data (or video data), speechdata and computer data between the mobile terminals MS1 and MS2.

[0034] The mobile terminals MS1 and MS2 are connected to each other bymeans of a physical layer (concretely, a mobile switching network NW).And data are transmitted in a packet called MUX-PDU as a unit. In theMUX-PDU, as shown in FIG. 2, a flag and a header are disposed on thehead end, and behind them the video data, speech data and computer dataare disposed alternately. Control information representing the contentsof the MUX-PDU is inserted into the header.

[0035] Above the physical layer an AL/MUX layer (concretely, a multipleseparation section) is disposed. In this AL/MUX layer the MUX-PDU isgenerated. Moreover, above the AL/MUX layer a higher-grade layer isdisposed. In this layer a video channel, an audio channel and a controldata channel are connected. The higher-grade layer is realized by meansof a multimedia processing section described later, a speech codecsection and a data communication section.

[0036] Video data are bundled and transmitted via the video channel. AMPEG-4 stream is embedded into the video channel. In this MPEG-4 stream,as shown in FIG. 4 described later, an I-Frame containing all thepicture elements of one picture is transmitted first. In the subsequentframe timings, P-Frames containing mainly difference data between acurrent frame and the preceding frame are transmitted sequentially.

[0037] Now, the mobile terminals MS1, MS2, . . . are composedrespectively as follows. FIGS. 3A and 3B show the appearance thereof,and FIG. 3A is a front view and FIG. 3B is a side view.

[0038] These mobile terminals MS1 and MS2 have a wireless TV phonecommunication function. On the front panel of the casing there aremounted a microphone 31, a speaker 32, a liquid crystal display (LCD) 34and a key input section 35. And a telescopic antenna 11 and a camera 33are provided on the top of the casing. This camera 33 employs a solidpickup device such as a CMOS or CCD and can pick up still pictures ormotion pictures. Further, on the rear of the casing there is provided abattery mounting section. A battery pack composing a power sourcesection 4 is detachably mounted in this mounting section.

[0039] Now, the circuit of the mobile terminals MS1, MS2, . . . iscomposed respectively as follows. FIG. 4 is a block diagram showing thecomposition.

[0040] That is, the mobile terminals MS1, MS2, . . . are composed of aradio section 1, a base band section 2, an input/output section 3 and apower source section 4 respectively.

[0041] Radio frequency signals coming from the base stations BS1, BS2, .. . over radio channels for the mobile communication system are receivedat the antenna 11 and are subsequently inputted into a receiving circuit(RX) 13 via a duplexer (DUP) 12. The receiving circuit 13 is providedwith a low-noise amplifier, a frequency converter and a demodulator.

[0042] And, after being amplified by means of the low-noise amplifier,the radio frequency signals are mixed with received local oscillatingsignals in the frequency converter and are down-converted into receivedintermediate frequency signals or received base band signals, and theoutput signals are demodulated digitally by means of the demodulator.Demodulation is carried out in steps of a primary demodulation and asecondary demodulation. As a primary demodulation scheme a spectrumreversed diffusion using diffusion codes is employed, and as a secondarymodulation scheme an orthogonal demodulation scheme complying, forexample, with a QPSK (Quadriphase Phase Shift Keying) scheme isemployed. Further, the received local oscillating signals are generatedby means of a frequency synthesizer (SYN) 14 according to theinstruction of a main control section 21A.

[0043] Demodulated data outputted from the demodulator are inputted intoa base band section 2. The base band section 2 is provided with a maincontrol section 21A, a multiple separation section 22, a voice codedecoding section (hereafter referred to as a voice codec) 23, amultimedia processing section 24, a temporary storage section 25, and amain storage section 26.

[0044] Among them, the temporary storage section 25 comprises, forexample, a ring buffer or FIFO (First-in First-out) memory, andaccording to the instruction of the main control section 21A, ittemporarily holds displaying video data reproduced by the decodingprocessing in the multimedia processing section 24 and non-decodedreceived picture frames outputted from the multiple separation section22.

[0045] The main storage section 26 comprises, for example, a RAM (RandomAccess Memory) or a EEPROM (Electrically Erasable and Programmable ReadOnly Memory), and according to the instruction of the main controlsection 21A, it selectively holds decoded displaying video data andnon-decoded received picture frames transferred from the temporarystorage section 25. Further, a portable flash EEPROM or the likedetachable from mobile terminals can be used in this main storagesection 26.

[0046] In the main control section 21A it is identified whether thedemodulated data are control information or multimedia information. As aresult of this identification, if the demodulated data are multimediainformation, they are inputted into the multiplex/demultiplex section 22and are divided here into received voice data and received video data.And the received speech data are inputted into the speech codec 23 andare decoded here into speech signals. These decoded speech signals areamplified and outputted from the speaker 32 of the input/output section3.

[0047] On the other hand, the received video data are inputted into themultimedia processing section 24 and are decoded into picture data byframe. These video data are fed to the liquid crystal display (LCD) 34of input/output section 3 and are displayed.

[0048] Further, various kinds of information indicating the operationalconditions of this apparatus outputted form the main control section 21Aare also displayed on this LCD 34. This displayed information includes,for example, a telephone book, a detected receiving electric fieldintensity value and a remaining amount of power in batteries.

[0049] On the other hand, the transmitted speech signals of a terminaluser outputted from the microphone 31 of the input/output section 3 areinputted into the speech codec 23 of the base band section 2A. And,after having been processed into encoded speech data here, they areinputted into the multiplex/demultiplex section 22. Further, the videosignals of the face of a terminal user picked up by the camera (CAM) 33are inputted into the multimedia processing section 24 of the base bandsection 2A. And, after having been processed into encoded video datahere, they are inputted into the multiplex/demultiplex section 22.

[0050] In the multiplex/demultiplex section 22, the encoded speech dataand the encoded video data are multiplexed according to a specifiedformat prescribed by ITU-T H.223 or the like. These multiplexedtransmitted data are inputted from the main control section 21A into thetransmitting circuit (TX) 15 of the radio section 1.

[0051] The transmitting circuit 15 is provided with a modulator, afrequency converter and a transmitted power amplifier. In the modulatortransmitted intermediate frequency signals are modulated digitally bythe transmitted data. Modulation is carried out in steps of a primarymodulation and a secondary modulation. As a primary modulation scheme,for example, a QPSK scheme is employed, and as a secondary modulationscheme there is employed a scheme in which signals after the primarymodulation are spectrum-diffused by means of diffusion codes. In thefrequency converter transmitted intermediate frequency signals modulatedby the modulator are mixed with transmitted local oscillating signalsand are up-converted into radio frequency signals with respect to thefrequency. Further, the transmitted local oscillating signals aregenerated by the frequency synthesizer 14 according to the instructionof the main control section 21A.

[0052] By means of the transmitted power amplifier the transmitted radiofrequency signals outputted from the frequency converter are amplifiedto a specified transmitted power level instructed by the main controlsection 21A. And they are fed to the antenna 11 via the duplexer 12 andare radiated from this antenna 11 towards base stations (not shown).

[0053] Further, in the power source section 4 there are provided abattery 41 using lithium ion cells, a charging circuit (CHG) 42 forcharging this battery 41, and a voltage generation circuit (PS) 43. Thevoltage generation circuit 43 comprises, for example, a DC/DC converterand generates a specified power source voltage vcc based on the outputvoltage of the battery 41.

[0054] And in the input/output section there is provided an illuminator36. This illuminator 36 is called, for example, a back light or anillumination and illuminates the LCD 34 and the key input section 35when a user operates keys or during communication.

[0055] The main control section 21A is provided with a microprocessorand an internal memory comprising a ROM, a RAM and the like. Further, itis newly provided with a displayed data recording control means 21 a inaddition to the usual control functions such as a connection controlfunction and communication control function of radio channels. Thesecontrol functions are realized by a control program contained in theROM.

[0056] This displayed data recording control means 21 a operates when auser carries out a video recording start operation in the input/outputsection 3 during TV phone communication operation. And in a period fromthe time of this video recording start operation to the time of thevideo recording end operation, display video data decoded and reproducedin the multimedia processing section 24 are fed to the main storagesection 26 via the temporary storage section 25 and are storedsequentially so that they may be displayed on the LCD 34.

[0057] Moreover, the displayed data recording control means 21 a hasalso a function of feeding display video data reproduced by means of adecoding processing at the time of the video recording start operationand each received picture frame outputted from the multiple separationsection 22 in a period from the time of the video recording startoperation to the time of the video recording end operation to the mainstorage section 26 via the temporary storage section 25 and of storingthem sequentially.

[0058] Now, the recording operations of received video data in themobile terminals MS1, MS2, . . . composed as described above will bedescribed.

(First Operation Example)

[0059] Suppose that the mobile terminal MS1 and the mobile terminal MS2shown in FIG. 1 start wireless TV phone communication using MPSG-4.Then, the mobile terminal MS1 generates first an I-Frame in the initialframe timing based on the video data outputted from the camera 33 andtransmits this I-Frame. And in each frame timing after the second frame,a P-Frame mainly composed of difference information between the videodata of the current frame and the video data of the previous frame isgenerated, and this P-Frame is transmitted sequentially.

[0060] On the other hand, the mobile terminal MS2 receives first theI-Frame transmitted from the mobile terminal MS1, reproduces one-picturedata in the multimedia processing section 24 based on this I-Frame anddisplays these one-picture data on the LCD 34. And in the subsequentframe timings respectively the P-Frames transmitted from the mobileterminal MS1 are received sequentially. And by adding these P-Frames tothe picture data reproduced by means decoding processing respectively inthe previous frames, the one-picture data are reproduced, and theseone-picture data are displayed sequentially on the LCD 34.

[0061]FIG. 5 shows an operation example of the video data transmissionscheme using the MPEG-4 in the form of a model. In the same figure,suppose that video data shown in V1, V2, V3, . . . are outputtedsequentially from the camera 33, for example, in the mobile terminal MS1of the transmitting side. Then the mobile terminal MS1 encodes first thepicture data V1 as still picture data and transmits the encoded picturedata obtained thereby as an I-Frame. On the other hand, the mobileterminal MS2 reproduces one-picture data V1, based on the receivedI-Frame and displays this on the LCD 34.

[0062] Next, each time the picture data V2, V3, . . . are outputted fromthe camera 33, the mobile terminal MS1 detects the differences betweenthese picture data V2, V3, . . . and the picture data V1, V2, . . . ofthe previous frame respectively. And picture data mainly composed ofthis difference information are generated respectively and these picturedata are transmitted as a P-Frame. On the other hand, each time theP-Frame is received, the mobile terminal MS2 adds the differenceinformation thereof to the display picture data V1′, V2′, . . . producedin the previous frames respectively, thereby reproducing one-picturedata. And these reproduced display picture data V2′, V3′, . . . ofone-picture are displayed sequentially on the LCD 34.

[0063] Now, suppose that a user has inputted a video recording startinstruction by operating the key input section 35, for example, in themobile terminal MS2 in a condition of carrying out the TV phonecommunication as described above.

[0064] Then the main control section 21A of the mobile communicationterminal MS2 feeds display video data reproduced by means in themultimedia processing section 24 to the main storage section 26 via thetemporary storage section 25 at this time and stores them in the mainstorage section 26. And the display data received subsequently till therecording end operation and reproduced in the multimedia processingsection 24 are respectively fed to the main storage section 26 via thetemporary storage section 15 sequentially and are stored in the mainstorage section 26. FIG. 6 shows how this recording operation is carriedout.

[0065] Therefore, even if the video recording start operation is carriedout in receiving a video data stream, display video data reproduced bythe decoding processing in the multimedia processing section 24 arerecorded sequentially in the main storage section 26 from the time ofthe operation. As a result thereof, when the display video data recordedin the main storage section 26 are reproduced, high quality video dataequivalent to the I-Frame can be reproduced from the time of the videorecording start operation.

(Second Operation Example)

[0066] In the first operation example described above, in the wholeperiod from the video recording start operation to the video recordingend operation, display video data decoded in the multimedia processingsection 24 and equivalent to the I-Frame are recorded in the mainstorage section 26.

[0067] However, the storage of display video data is not limitedthereto. For example, as shown in FIG. 7, only at the time of the videorecording start, display video data decoded in the multimedia processingsection 24 and equivalent to the I-Frame are recorded in the mainstorage section 26. And in the subsequent period till the videorecording end operation, received picture frames, that is, P-Frames, maybe stored in the main storage section 26.

[0068] By doing this, over the whole period from the video recordingstart operation to the video recording end operation, in comparison tothe case in which display video data decoded in the multimediaprocessing section 24 and equivalent to the I-Frame are recorded, theamount of video data recorded in the main storage section 26 can bereduced substantially. As a result thereof, the storage capacity of themain storage section 26 can be used effectively, thereby prolonging therecording time of video data.

(Second Embodiment)

[0069] In a second embodiment of the present invention, at the time of avideo recording start operation carried out by a user, display videodata reproduced by a decoding processing in the multimedia processingsection are returned to the multimedia processing section, arere-encoded into an I-Frame and are subsequently stored in the mainstorage section. Further, in a period from the time of the videorecording start operation to the time of a video recording endoperation, display video data reproduced by a decoding processing in themultimedia processing section are returned to the multimedia processingsection, are re-encoded into P-Frames and are stored in the main storagesection.

[0070]FIG. 8 is a block diagram showing the functional organization of amobile terminal having an encoded data recording function according tothe second embodiment. Further, in the same figure, the identicalsections to FIG. 4 are marked with the identical symbols, and detaileddescriptions will be omitted.

[0071] The main control section 21B of a base band section 2B isprovided with a displayed data recording control means 21 b and are-encoding control means 21 c as new control functions according to thepresent invention.

[0072] When a video recording start operation is carried out in theinput/output section 3 during communication, the displayed datarecording control means 21 b carries out main processing operations forstoring display video data reproduced by a decoding processing in themultimedia processing section 24 in the main storage section 26 for aperiod from the time of this video recording start operation to the timeof a video recording end operation.

[0073] When the displayed data recording control means 21 b stores thedisplay video data in the main storage section 26, the re-encodingcontrol means 21 c returns these display video data to be recorded tothe multimedia processing section 24 and re-encodes them. And an I-Frameand P-Frames generated by this re-encoding are stored in the mainstorage section 26.

[0074] In such a composition, supposes that a user carries out a picturerecording start operation during TV phone communication. Then the maincontrol section 21B inputs display video data reproduced by means of adecoding processing in the multimedia processing section 24 into theencoding section in the multimedia processing section at the time ofthis video recording start operation. And an I-Frame obtained by are-encoding processing in this encoding section is stored in the mainstorage section 26 via the temporary storage section 25.

[0075] For a period till a user carries out a video recording endoperation, each time display video data are reproduced by a decodingprocessing of the multimedia processing section 24, the display videodata are inputted into the encoding section in the multimedia processingsection 24 and are re-encoded. And P-Frames generated by thisre-encoding processing are stored sequentially in the main storagesection 26 via the temporary storage section 25.

[0076]FIG. 9 shows how the recording operation of video data using thisre-encoding processing is carried out.

[0077] Further, for a period from the video recording start operation tothe video recording end operation, the main control section 21B stopsthe encoding processing of transmitted video data in the multimediaprocessing section 24 temporarily for re-encoding display video data.

[0078] As described above, according to the second embodiment, displayvideo data reproduced by a decoding processing in the multimediaprocessing section 24 are re-encoded in the multimedia processingsection 24 and are recorded in the main storage section 26. Therefore,the received video data can be recorded in a compressed condition.Accordingly, the amount of video data recorded in the main storagesection 26 can reduced. As a result thereof, the storage capacity of themain storage section 26 can be used more effectively, thereby prolongingthe recording time of video data.

[0079] Moreover, the re-encoding processing of display video data iscarried out in the encoding section of the existing multimediaprocessing section 24. Therefore, no encoder for re-encoding is newlyrequired. Accordingly, a mobile terminal with larger-sized circuitry canbe avoided.

(Third Embodiment)

[0080] In a third embodiment according to the present invention, when auser carries out a video recording start operation during wireless TVphone communication using MPEG-4, display video data reproduced by adecoding processing in the multimedia processing section for a periodfrom the time of this picture recording operation to the time of apicture recording end operation are held temporarily in the temporarystorage section. And, after the end of the TV phone communication, thedisplay video data held in the temporary storage section are read out,are inputted into the multimedia processing section and are re-encodedinto an I-Frame and a plurality of subsequent P-Frames. And the I-Frameand the plurality of subsequent P-Frames obtained by means of thisre-encoding are stored in the main storage section.

[0081]FIG. 10 is a block diagram showing the functional organization ofa mobile terminal having an encoded data recording function according tothe second embodiment. Further, in the same figure, the identicalsections to FIG. 8 are marked with the identical symbols, and detaileddescriptions will be omitted.

[0082] The main control section 21C of a base band section 2 c isprovided with a displayed data holding control means 21 d, a displayeddata recording control means 21 e and a re-encoding control means 21 fas new control functions according to the present invention.

[0083] When a user carries out a video recording start operation duringwireless TV phone communication, display video data reproduced by adecoding processing in the multimedia processing section 24 for a periodfrom the time of this video recording start operation to the time of avideo recording end operation are held temporarily in the temporarystorage section 25.

[0084] The displayed data recording control means 21 e monitors the endof the wireless TV phone communication. And the communication comes toend, the display video data held in the temporary storage section 25 areread out and are inputted into the multimedia processing section 24. Andan I-Frame and P-Frames obtained by this re-encoding processing in themultimedia processing section 24 are stored in the main storage section26.

[0085] The re-encoding control means 21 f controls the operation of themultimedia processing section 24 and re-encodes the display video dataread out from the temporary memory section 25.

[0086] Due to such a composition, when a video recording start operationis carried out during communication, display video data decoded by themultimedia processing section 24 for a period from the time of thisvideo recording start operation to the time of a video recording endoperation are transferred to the temporary storage section 25 and areheld therein under control of the main control section 21C. Andsubsequently, when the end of communication is detected, the displayvideo data held in the temporary storage section 25 are read outsequentially in order of time under control of the main control section21C, are inputted into the encoding section of the multimedia processingsection 24 and are re-encoded into an I-Frame and subsequent P-Frames.And these re-encoded I-Frame and P-Frames are stored in the main storagesection 26 via the temporary storage section 25.

[0087] Therefore, according to the third embodiment, as in the secondembodiment, since display video data are re-encoded in the multimediaprocessing section 24 and are recorded in the main storage section 26,the received video data can be recorded in a compressed condition.Accordingly, the amount of video data recorded in the main storagesection 26 can reduced. As a result thereof, the storage capacity of themain storage section 26 can be used more effectively, thereby prolongingthe recording time of video data.

[0088] Further, in the third embodiment, the re-encoding processing iscarried out after the end of communication. Therefore, the re-encodingprocessing of video data to be recorded is permitted without stoppingthe encoding processing of transmitted data by the multimedia processingsection 24 temporarily. Moreover, the processing load of the maincontrol section 21C can be reduced, and therefore, no CPU or DSP havinga high processing capability is required.

(Other Embodiments)

[0089] In the second embodiment, when display video data are re-encodedin the multimedia processing section 24, the encoding processing oftransmitted data is stopped temporarily. However, the multimediaprocessing section 24 has a sufficient signal processing capability, theencoding processing of transmitted picture data and the re-encodingprocessing of display video data may be carried out in time sharing.

[0090] As a result thereof, received video data can be recordedconcurrently with video data being transmitted. Further, after the endof communication, recorded received picture data can be reproducedinstantaneously.

[0091] Moreover, another video encoder for re-encoding display videodata may be provided in addition to the multimedia processing section 24and the re-encoding processing of display video data may be carried outby this picture encoder. In this case, as a video encoder forre-encoding display video data, an encoder permitting a higher-qualityencoding such as a MPEG-2 encoder is preferably used.

[0092] Further, as an encoding compression/extension scheme of videodata, other schemes such as ITU-T H.263 or the like than MPEG-4 may beemployed, and with respect to data to be transmitted, still video dataand other data may be transmitted in addition to motion picture data.

[0093] Further, in the above-described embodiments, a case in whichwireless TV phone communication is maintained between the mobileterminals MS1 and MS2 is described. However, in addition thereto, thepresent invention is also applicable, for example, to a case in which amobile terminal is connected to a WWW server or the like on Internet viaa network NW and information contained in a home page or the like isdown-loaded from this server. Moreover, the present invention is alsoapplicable to a case in which an electronic mail accompanied by motionpicture data is received.

[0094] In the above-described embodiments, a mobile communication isdescribed as an example. However, the present invention can be appliedto a radio transmission system and the like between equipment using ashort distance radio data transmission scheme represented by wirelessLAN and BT (Bluetooth), and further it may be applied to a cabletransmission system such as a subscriber network using metallic cablesor optical fiber cables and a cable television broadcasting network.

[0095] Moreover, as an encoded data recording apparatus, a recorder orthe like recording video data or audio data received by a televisiontuner or a car radio is included in addition to communication terminalssuch as a mobile terminal, a PDA and a personal computer.

[0096] Further, as an encoded data input means, means acquiring datafrom a mobile recording medium such as a CD, a DVD or a memory card areincluded in addition to means into which encoded data are inputted froman external equipment by using a cable or a radio link.

[0097] And besides, it is to be understood that various changes in thekind and the composition of terminals, the construction of a re-encodingmeans and the like may be made without departing the summary of thepresent invention.

Industrial Applicability

[0098] As described above in detail, in the present invention, when adata display control means for receiving first data and second data,reproducing frame data of each frame based on these data and displayingthe frame data sequentially on the display is provided, at least thenewest frame data are held temporarily in the data holding means eachtime frame data are reproduced by this data display control means. Andwhen a recording instruction of the received data is inputted inreceiving the first data and the second data, reproduced frame data heldtemporarily in the data holding means are recorded in a recording mediumin the order corresponding to the time of having inputted the recordinginstruction.

[0099] Therefore, according to the present invention, there can beprovided an encoded data recording apparatus and a mobile terminalcapable of recording high-quality data immediately after having inputteda recording instruction by using reproduced display frame data even ifrecording is begun in receiving data.

1. An encoded data recording apparatus for recording encoded datacomposed of first data generated based on original data havingcorrelations on the time axis in an initial frame timing thereof and ofa plurality of second data generated respectively in a plurality offrame timings subsequent to said initial frame timing, said first datahaving an independent meaning alone and said plurality of second datacontaining mainly a difference between the original data of a currentframe and the original data of the preceding frame respectively, saidapparatus comprising: encoded data input means for inputting saidencoded data; data reproduction processing means for reproducing saidoriginal data based on the first data and the second data of the encodeddata inputted by means of this data input means; recording periodspecifying means for specifying the recording period of said encodeddata; and recording control means for recording the original datareproduced by said data reproduction processing means in the recordingperiod concerned in a recording medium when the recording period isspecified by said recording period specifying means in period inputtingsaid encoded data.
 2. The encoded data recording apparatus according toclaim 1, wherein said recording control means records the original datareproduced by said data reproduction processing means in a recordingmedium in the first frame timing of said recording period and recordsthe second data inputted by said encoded data input means in saidrecording medium in the frame timings subsequent to said first frametiming.
 3. The encoded data recording apparatus according to claim 1,wherein said recording control means comprises: re-encoding means forre-encoding the original data reproduced by said data reproductionprocessing means in said recording period into first data and aplurality of second data; and means for recording the first data and theplurality of second data obtained by said re-encoding means in saidrecording medium.
 4. The encoded data recording apparatus according toclaim 1, wherein said recording control means comprises: recorded dataholding means for holding the original data reproduced by said datareproduction processing means in said recording period temporarily tillthe input period of said encoded data comes to an end; and means forre-encoding the original data held temporarily in said recorded dataholding means into first data and a plurality of second data andrecording them in said recording medium after the input period of saidencoded data has come to an end.
 5. A mobile terminal for receiving overradio channels and recording encoded data composed of first datagenerated based on the original data having correlations on the timeaxis in the initial frame timing thereof and of a plurality of seconddata generated respectively in a plurality of frame timings subsequentto said initial frame timing, said first data having an independentmeaning alone and said plurality of second data containing mainly adifference between the original data of a current frame and the originaldata of the preceding frame respectively, said mobile terminalcomprising: radio receiving means for receiving encoded data transmittedover said radio channels; data reproduction processing means forreproducing said original data based on the first data and the seconddata of the encoded data received by said radio receiving means;recording period specifying means for specifying the recording period ofsaid encoded data; and recording control means for recording theoriginal data reproduced by said data reproduction processing means inthe recording period concerned in a recording medium when the recordingperiod is specified by said recording period specifying means inreceiving said encoded data.
 6. The mobile terminal according to claim5, wherein said recording control means records the original datareproduced by said data reproduction processing means in a recordingmedium in the first frame timing of said recording period and recordsthe second data of the encoded data received by said radio receivingmeans in said recording medium in the frame timings subsequent to saidfirst frame timing.
 7. The mobile terminal according to claim 5, whereinsaid recording control means comprises: re-encoding means forre-encoding the original data reproduced by said data reproductionprocessing means in said recording period into first data and aplurality of second data; and means for recording the first data and theplurality of second data obtained by said re-encoding means in saidrecording medium.
 8. The mobile terminal according to claim 7, wherein,when transmission encoding means for encoding the original data to betransmitted into first data and a plurality of second data andtransmitting them wirelessly is provided, said transmission encodingmeans functions also as said re-encoding means.
 9. The mobile terminalaccording to claim 5, wherein said recording control means comprises:recorded data holding means for holding the original data reproduced bysaid data reproduction processing means in said recording periodtemporarily till the receiving period of said encoded data comes to anend; re-encoding means for re-encoding the original data heldtemporarily in said recorded data holding means into first data and aplurality of second data after the receiving period of said encoded datahas come to an end; and means for recording the first data and theplurality of second data obtained by said re-encoding means in saidrecording medium.
 10. The mobile terminal according to claim 9, wherein,when a transmission encoding means for encoding the original data to betransmitted into first data and a plurality of second data andtransmitting them wirelessly is provided, said transmission encodingmeans functions also as said re-encoding means.
 11. The mobile terminalaccording to claim 5, wherein said data reproduction processing meansreproduces original data according to a data decoding scheme specifiedin MPEG-4 (Moving Picture Experts Group-4).